Mr. Oliver has curly hair, which is dominant trait (C). Mrs. Oliver also has curly hair. Mr. Oliver has two dominant genes (Cc) and Mrs. Oliver has one dominant gene and one recessive gene (Cc), their child might have either combination, CC or Cc. Because there are no cc or straight hair combinations, all their children will have curly hair.

Mr. Kim is tall, which is a dominant trait (T). Mrs. Kim is short, which is recessive trait (t). Mr. Kim has two recessive genes (tt).

Mr. Sandez has green eyes, which is a recessive trait (b). Mrs. Sandez has brown eyes, which is a dominant trait (B). Mr. Sandez has two recessive genes (bb) and Mr. Sandez has two dominant genes (BB)